The easiest way to install crmsh is via the package manager of your distribution.
SLES / openSUSE
Red Hat / CentOS / Fedora
We try to build Red Hat / CentOS / Fedora-compatible RPM packages on the OBS (see above).
--- dnf config-manager --add-repo http://download.opensuse.org/repositories/network:/ha-clustering:/Stable/CentOS_CentOS-7/network:ha-clustering:Stable.repo ---
The versions of crmsh and pacemaker currently available in the latest Debian release are quite old. Newer packages are available via the Debian-HA team wiki and the distribution packages will hopefully be updated soon.
Packages for crmsh are available from the Launchpad.
A fairly up-to-date version is available here.
crmsh is available via the AUR. Unfortunately the package seems somewhat out of date.
Releases are available as .tar.gz or .zip archives via Github.